This invention relates to folding bicycles, and more particularly to a folding bicycle having elongated supporting members which carry substantial loads during operation of the bicycle.
A bicycle of this general type is shown in the copending application of David T. Hon, Ser. No. 233,624, filed Feb. 12, 1981, now U.S. Pat. No. 4,433,852, issued Feb. 28, 1984 with a relatively low folding frame and a folding handlebar assembly with an elongated steering post carrying a handlebar at its upper end and having a hinge and latch at its lower end. The post is swingable between a lowered position alongside the front wheel and a raised, operating position in which the post is latched when the bicycle is to be ridden.
In bicycles of this type, lightness in weight is important for ease of carrying the bicycle in the folded condition, so structural members should be made as light as possible. On the other hand, all load-bearing members must be capable of supporting the loads to which they will be subjected in use, without objectionable flexing, bending or, of course, breaking.
The handlebar assembly is of particular concern, because of the forces to which it is subjected during pedaling, turning and stopping. Where elongated handlebar assemblies are used, as with low frames making possible very compact folding, it is necessary either to make the assembly very strong, and consequently relatively heavy, or to brace it against operational forces, so that a lighter assembly may be used.
One example of bracing in a prior foldable bicycle is shown in Lassiere U.S. Pat. No. 3,979,136, with a foldable stay, either single or a rectangular frame, that is hinged between its ends to fold in two as the braced member is folded. Another type of bracing approach is shown in Jensen U.S. Pat. No. 3,623,749, with a relatively heavy, generally rectangular bracing frame that telescopes, extending and contracting as the braced member is folded.
The primary objective of the present invention is to provide an improved lightweight brace assembly for use in a folding bicycle of the general type shown in the Hon application, and particularly for bracing the handlebar assembly, which very effectively braces the handlebar, both longitudinaly and laterally, and permits quick and easy folding of both the brace and the handlebar assembly into a compact form.